After writing a recent post about the illusion of free will, "Simple task shows why free will is an illusion," a comment on the post included this:
Mind blown because I assumed atheists believed in free will too. Thought the whole notion of not having free will was part of a mystical “everything is karma” sort of ideology.
Sam Harris, who thought up the simple task I described in the post, is both a noted atheist and a strong advocate for free will being an illusion. Or delusion.
Harris published "The End of Faith" in 2005. In 2012 he published "Free Will," which argues for its illusory nature. I've read and enjoyed both books, so to me it is perfectly natural that atheists don't believe in free will, since that describes me also -- an atheist who rejects the illusion of free will.
Today I listened to Part 2 of Harris' talk about free will on his Waking Up iPhone app. In it he describes a conversation he had with a rabbi.
The rabbi told Harris that free must exist so humans can choose between doing good and evil. Plus, I assume, between believing in God and not believing in God. Here's a Judaic take on free will:
Free will in Judaism is the capacity to choose between different courses of actions, words or thoughts—not due to outside influence, internal nature or any sort of personal preference. Just a balanced choice between right and wrong.
This notion that human beings can exercise their own free will when making moral decisions is axiomatic to Judaism. And the conflict between human free will and the omnipotence of his Creator is a pervasive theme in the Jewish narrative of history.
...The Hebrew Bible is a story of G‑d’s interaction with man. G‑d rewards those who listen to His will and help perfect His world; He chastises those who disobey and destroy it. The choice to do one or the other is clearly in our hands. “Behold,” G‑d says, “I have placed before you good and evil, life and death. Choose life! Without a belief in free will, none of this would make sense. There could be no instructions, no reward, and no chastisement.
But as with all things relating to religiosity, there's a lot of confusion about how free will relates to God or the divine. Just scroll through the Wikipedia article, "Free will in theology," and you'll see what I mean.
In both Western and Eastern religions there's much debate about how free will can coexist with God's omniscience/omnipotence, destiny, and such. Of course, this isn't surprising, since there is no evidence that God or a supernatural divinity even exists, so obviously this makes it tough to figure out how free will relates to a nonexistent entity.
With regard to atheism, I'm sure many atheists do believe in free will, since this is the default human condition.
Meaning, unless someone studies neuroscience and psychology, and carefully observes their own mind in the way Sam Harris describes in his "think of a movie" exercise, they're going to continue to believe they have free will, since this is how it seems to us (much as it seems the Sun rises and sets, while actually the Earth is rotating).
But as Harris observes in his Waking Up talks about free will, determinism is more compatible with an atheist view of reality. We don't choose our parents, and thus our genetic heritage. We don't choose the culture we grow up in. We don't choose the laws of nature. We don't choose the structure and functioning of our brain.
Yet all of these things, and so much more, affects how we think, feel, decide, and in general, look upon the world. Thus free will seems to require a dualistic conception of reality.
This is reflected in the Wikipedia article mentioned above, which says that in Hinduism, Advaita (which is monistic) generally believes in a fate-based approach, while Dvaita (dualistic) schools are proponents of free will.
By and large, atheists view humans as being an integral part of nature, and of the universe. Whatever forces operate upon other entities in the world, these same forces impact human beings. I love this conception, because it points toward an inherent oneness and interdependency.
In contrast, most religions view this world as a pale shadow of heavenly realms, and humanity as being "fallen" or sinful, and thus needing redemption by a savior, guru, spiritual guide, or whatever. Free will serves as a rationale for why a good God would leave humans in such a sorry state: we chose to distance ourselves from God, so now we're reaping the consequences of this bad decision.
This doesn't make sense, along with other aspects of religion. But religious believers accept a lot of theological nonsense, with a belief in free will being part of that dogma.
Just think about it: how could our will truly be free?
Meaning, not under the influence of our prior experiences, knowledge, values, desires, etc., etc. There would have to be some sort of free will fairy dust floating around inside our head that somehow stood completely apart from all of the causes both inside and outside of us that otherwise affect our thoughts and actions.
This is why dualism is the only refuge of those who believe in free will, because the human brain clearly operates under the dictates of the laws of nature. So religious believers imagine that a soul or spirit magically is responsible for our free will. Of course, as Sam Harris notes in his talks, we don't choose this soul.
Thus as ridiculous as a belief in soul is, even this doesn't support a belief in free will. Nothing does, which is why most of us who embrace reality, rather than religion, consider free will to be an illusion.